Ultraviolet Spectrum of TiI

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA

Ultraviolet Spectrum of TiitCHRISTOPHER M. WILSON AND MATTHEW P. THEKAEKARA

Georgetown University,* Washington, District of Columbia

Four hundred and ten lines of the ultraviolet spectrum, from 2117 A to 3072 A, have been measured inthis study, with a probable error of 0.005 A, on high-dispersion quartz-prism spectrograms. A small electroniccomputer, the Burroughs E101, has been used to great advantage in calculating the wavelengths ani wavenumbers and in analyzing the spectrum. Two new terms have been discovered. Two hundred and fourteenlines have been classified, of which 152 were previously known. The energy values for 16 levels of sevenpreviously known terms have been revised.

I. INTRODUCTION

THE development of electrodeless discharge lamps'and the advent of automatic techniques in

spectroscopy2 have made feasible more detailed andmore accurate analyses of atomic spectra. Althoughtitanium has been analyzed more extensively thanmany elements, the analysis is still far from complete,particularly in the ultraviolet. For this reason, andbecause of its astrophysical importance, the spectro-scopic staff of the Georgetown College Observatoryhas undertaken a new study of the spectrum Ti I. Alist of 113 new lines of Ti I, in a region ordinarilymasked by the a bands of TiO, has previously beenpublished in this Journal.' More recently, a revised andenlarged set of interferometric values for Ti I terms,making use of Edlen's new formula for the dispersion ofstandard air,4 has been completed. 5

The present paper is the result of the application ofautomatic techniques developed at the Observatory tothe reduction of a set of spectrograms made by C. C.Kiess at the National Bureau of Standards in 1933.It was known that these plates contained much newinformation, since their dispersion is exceptionally highfor the ultraviolet region. However, the amount of workinvolved made their reduction impracticable before thedevelopment of the automatic techniques.

II. SPECTROGRAMS

The spectrograms were exposed in a Hilger quartz-prism spectrograph which carries a large 60° Cornuprism in combination with a 30° reflecting prism in theE185 mounting.6 The length of the path of the lightrays in the quartz is about 45 cm, and the dispersionobtained is better than 1 A per mm. By means of a

t The publication of this paper has been subsidized by a grantfrom Georgetown University.

*Supported in part by National Science Foundation grant.'C. H. Corliss, W. R. Bozman, and F. 0. Westfall, J. Opt. Soc.

Am. 43, 398 (1953).2 G. H. Dieke, D. Dimock, and H. M. Crosswhite, J. Opt. Soc.

Am. 46, 456 (1956). (A number of other references may be foundin this article.)

3 A. K. Wardakee, J. Opt. Soc. Am. 45, 354 (1955).4 B. Edl6n, J. Opt. Soc. Am. 43, 339 (1953).'C. C. Kiess and M. P. Thekaekara, Astrophys. J. 130, 1008

(1959).6 C. C. Kiess, J. Research Natl. Bur. Standards 47, 385 (1951).

Hartmann diaphragm, three spectra, Ti arc, Fe arc, andTi spark, were exposed, in that order.

The lines were measured manually and visually onthe type 0212 astrographic comparator of the Socit6Genevoise. The positions were read and recorded by anautomatic recording instrument, the Telecordex. Thisinstrument and its advantages have already beendescribed in this Journal.2 Each plate was measuredfour times-twice in each direction. More than half, ofthe lines were measured on two plates and the re-mainder on one.

III. USE OF A SMALL COMPUTER

The calculations required to obtain the wavelengthsand wave numbers from the position values and thosenecessary for the classification of the lines were per-formed by the Burroughs E101 electronic computerillustrated in Fig. 1. Similar programs are found in theliterature, but in general they have made use of largeand expensive computer installations. The E101, on theother hand, is about the size of a large office desk andwithin the means of smaller research groups. In addition,the programming and operation of the machine arelearned rather easily, so that each individual can beresponsible for the calculations connected with his own

QPERf A 0 : 0 00 0 i f O ; :S PRINTIRO

KEY AR

PUNCH : GR 0000 :t0

THE ELECTRODATA 101ELECTRONIC COMPUTER

FIG. 1. The E101 computer used in preparing this paper is thesize of a large office desk (exclusive of the tape punch unit, whichwas not used).

289

VOLUME 51, NUMBER 3 MARCH, 1961

C. M. WILSON AND M. P. THEKAEKARA

rI

____________________ 4

Fie. 2. A paper template used in programming the E101. Thisis placed over a pinboard and a pin placed in each marked hole.Each horizontal line gives one instruction to the machine; e.g.,the first line (W31) instructs the machine to place the numberobtained in the previous step in memory location 31.

project, and the results are available immediately.Thus, further stages of experiment or computation canbe planned without the long delays involved in waitingone's turn for the time of a large computer and its staff.

The input of the machine is through an 11-columnkeyboard similar to that of a desk calculator. Keyboardentries and the results of the computation are printedon a continuous roll of paper in a variety of formats,depending on the needs of the problem. A total of 220words (12 digit numbers) can be stored in the magneticdrum memory, from which they can be recalled at anytime. Instructions are given the machine through pinsettings in eight removable pinboards such that a totalof 128 operations can be presented at one time. Theinstruction symbols follow an obvious code, +,-,X., P for printout, R for read from the memory, etc.

Paper templates, placed over the boards, are used topreserve the programs and to ensure rapid setting of thepins. Figure 2 is a photograph of one of the templatesused in the present program. In addition to the ordinaryoperations, there are transfer instructions which directthe machine from any given step to any other step inthe program. In this way, the same portion of theprogram can be utilized at various points in the problemand many times in succession. Hence the number ofinstructions actually presented to the computer byone set of eight boards may be several times greaterthan 128. To illustrate the speed of operation, a typicalprogram (requiring 12 boards) may be cited. Given tensets of values of position x and wavelength X, theconstants a, b, c of the quadratic equation, X=a+bx+cx 2 , which give the best fit for these pointsare to be calculated. Normal equations must be con-structed and the constants determined by the methodof least squares. On the desk calculator this would takeseveral hours, while on the E101 the solution is foundand the results printed out in 24 min from the time thevalues of x and X have been keyed.

Besides its use in the calculation of wavelengths andwave numbers, according to the programs to be de-scribed shortly, the E101 has been used in a variety of

ways in the preparation of this paper. For instance,known upper and lower levels can be stored in themachine along with certain of the selection rules, andit then computes and prints out the wave numbers ofexpected transitions. Again, a list of the wave numbersof unclassified lines and the differences between knownlower levels can be stored and the computer instructedto comb the list for lines with the specified differences.From these it constructs a list of tentative upper levelswhich can be used to establish new terms.

IV. CALCULATION OF WAVELENGTHS ANDWAVE NUMBERS

The conventional method of obtaining wavelengthsfrom measurements on a prism plate is by the modifiedHartmann dispersion formula

>,XoA+E[ca (x-xo)1.

Generally a 25-cm plate is divided into three parts; theplate constants Xo, C, and xo are calculated for eachpart, and a calibration curve is drawn. At best, this is atiresome process, and it is open to considerable errordue to the drudgery involved and to poor judgment inthe construction of the curve.

It was decided that the calibration curve could beeliminated if the plate were divided into 10 or 15 regionsrather than three and if, in each of these smallerregions, the quadratic equation, =a+bx+cx 2 , whichgave the best fit for 20 iron lines was obtained by themethod of least squares. No attempt was made to justifythis method theoretically. It was based on the reasonableassumption that the true dispersion curve of the prismcould be approximated for small regions by a quadratic,and this was verified by a number of trials. A satis-factory solution was taken to be one for which thedifferences between listed and calculated wavelengthswere randomly plus and minus and of the order of theerrors in measurement, that is, less than 0.005 A formost lines. If the differences in one or another regionshowed a bias towards plus or minus, or if several ofthem were especially large, it was assumed that thiswas due to poor measurement, to wrong identificationof one or more of the lines, or to errors in the listedwavelengths. This assumption was verified by the factthat a satisfactory solution was obtained when theoffending line or lines were replaced.

It is obvious that this method requires that a largenumber of iron lines be used as standards-not merelythose accepted as secondary standards by the Inter-national Astronomical Union. In fact, all of the linesfound on the plates which were listed to three places,either on Gatterer's map-of the iron spectrum' or in thelist of Russell and \Ioore,5 were so used. A small

I A. Gatterer, Grating Spectrum of Iron (Specola Vaticana,Vatican City, 1951).

8 H. N. Russell, C. E. Moore, and D. W. Weeks, The Arc Spec-tr1om of Iron (American Philosophical Society, Philadelphia, 1944).

:IA- I

I' I

*t0!

Vol. 51290

ULTRAVIOLET SPECTRUM OF Tii

number known to two places was also used. It ispossible that there are large errors in the listed wave-lengths of some of these lines. However, it is not likelythat a group of 20 of them (including, generally, one ormore of the secondary standards) could all be in-accurate in such a way that the curve obtained fromthem would differ appreciably from the true dispersion.

The method just described is so complex as to havebeen impracticable if a computer were not available.With the EtOl, however, it is quicker and considerablyless tiresome than is the normal method using a deskcalculator. The positions and wavelengths of the 20standard iron lines are keyed into the E101, which thenconstructs the normal equations and solves them fora, b, and c. Using these constants, the computer calcu-lates the wavelengths and finally prints out the standardwavelengths, the calculated wavelengths, and thedifferences between them. If these differences indicatethat the calculated constants are not satisfactory, oneor more of the standard lines is replaced and thecalculations repeated. A printout sheet illustratingthis portion of the program is reproduced in Fig. 3.If the constants are satisfactory, position values of thetitanium lines in the region are keyed in, and thecomputer calculates the wavelengths. This process ofdetermining the constants of a section of the plate andcalculating the wavelengths of the Ti lines-includingthe keying, which takes most of the time--consumesabout 15 min.

The E101 was also used to calculate the wavenumbers directly from the wavelengths. The computerwas programed so that it took a keyed-in wavelengthand used it to calculate the wave number approximately.Taking this approximate value, it calculated therefractive index of air n according to Edl6n's formula4

and used the n so calculated and the wavelength toobtain the vacuum wave number. The error introducedby using the approximation for the wave number inthe first step can be shown to affect only the fourthdecimal place of the final wave number.

The titanium sources used in making the platescontained a number of impurities whose lines had to beeliminated. Lines due to iron and Ti ii were eliminatedin the measuring process through comparison with theexposures of these spectra on each plate. The remaininglines were first checked against the principal lines9 of allelements that were likely to be present as impurities andfinally against the complete MIT Wavelength Tables."They were also compared with the band-heads oftitanium oxide and with the list of 1381 band-heads

I Handbook of Chemistry and Physics, edited by C. D. Hodgman(Chemical Rubber Publishing Company, Cleveland, 1954).

10 Massachusetts Institute of Technology Wavelength Tables,measured and compiled under direction of G. R. Harrison (JohnWiley & Sons, Inc., New York, 1939).

11 R. W. B. Pearse and A. G. Gaydon, The Identification ofMolecular Spectra (Chapman and Hall, Ltd., London, 1941).

FIG. 3. Printout sheet from the E101, which illustrates aportion of the process used to obtain the constants of a quadraticequation by means of which the Ti wavelengths may be calculated.(Only the numbers and the minus signs appear on the originalsheet.) Here, the final set of constants is such that the largestdifference between the calculated and standard wavelengths ofthe iron lines is about 0.0055 A.

that are most likely to be found in arc spectra." Onehundred and sixty-nine lines, out of a total of 579, wereeliminated as being due to vanadium, silicon, nickel,aluminum, magnesium, chromium, and zirconium.

12 Work cited in footnote 10, p. vii.

291March 1961

C. M. WILSON AND M. P. THEKAEKARA

V. CLASSIFICATION OF LINES

In the region covered by this paper, the only linespreviously classified are the 178 listed by Russell.3

They are grouped in 54 multiplets and are due totransitions between the levels of 45 terms. As a firststep in the classification of the 410 lines accepted asbeing due to Ti i, an attempt was made to identify these178 lines by means of a comparison of the wave numbersand intensities from the two lists. One hundred andfifty-two were found. The remaining 26 were not on theplates or were masked by lines due to the impurities.

An examination of the 1400 Ti classifications listedby Russell shows that none of them violate the Laporterule nor the selection rule for J. Theoretically, also,such violations are extremely unlikely. The E101 wasprogramed to find all possible transitions betweenknown energy levels which lay within the rangecovered by the plates and did not violate these rules.The values for the energylevels were taken fromMoore.14

Then the wave numbers of the 258 unclassified lines werecompared with these possible transitions. Tentativeclassifications were assigned to those which coincidedwithin 0.5 cm-'. This tolerance was determined by anexamination of the agreement between observed andcalculated wave numbers for the 152 previouslyclassified lines. Such a tolerance is not large for linesin this short wavelength region. Russell alloweddiscrepancies as large as 0.9 cm-', and, while the newmeasurements are more accurate, the calculated valuesare derived from energy level values established chieflyby Russell on the basis of the measurements which helists.

The tentative classifications were judged in the light -of the selection rules for L and S and the variousintensity rules. Forty-seven of them were finallyaccepted as genuine. Thus 199 lines out of 410 wereclassified on the basis of known levels.

TABLE I. s3G0 multiplets. The energy level values are below thedesignations. The calculated wave number for each transition isin parentheses. The observed intensities are in parentheses afterthe observed wave numbers. Observed and calculated intervalsare italicized.

s3G31 s3G4I s3Gs046 725.42 112.67 46 838.09 136.56 46 974.65

a3F2 46 725.40 (6)0.00 (46 725.42)

a3F3 46 555.37( -) 112.59 46 667.96(6)170.13 (46 555.29) (46 667.96)a3F4 46 451.22(1) 136.56 46 587.78(7)386.87 (46 451.22) (46 587.78)

b'F211531.76b3Fa 35 085.56(0) 112.51 35 198.09(-)

11639.80 (35 085.62) (35 198.29)b3F4 35 19809(-)

11776.81 (35 197.85)

13 H. N. Russell, Astrophys. J. 66, 347 (1927).14 Atomiic Energy Levels, edited by C. E. Moore, National

Bureau of Standards Circ. No. 467 (U. S. Government PrintingOffice, Washington, D. C., 1948), Vol. 1.

VI. ACCURACY OF THE MEASUREMENTS

A probable error computed from the measurementson each line would have little significance, since noneof the lines were measured on more than two plates.However, comparison of successive measurements andof wavelength values from different plates-for thoselines which appeared on two plates-indicated thatthe probable error was about 0.005 A. Once the 152previously classified lines had been identified it waspossible to confirm this and, at the same time, to checkthe consistency of the measurements.

Among the 152 lines there are 22 pairs which are dueto transitions from 22 upper levels to both the a'F2 anda3F3 levels. Thus there are 22 values for the a 3 F3-a 1F2energy difference. Likewise there are 21 values for thea3 F4 -a'F 3 difference. The probable error for the 22a3 F3 -a3 F2 value is 0.108 cm-'. For the a3F4 -a3 F3values it is 0.085 cm-'. Since each of the intervals is afunction of two measured lines, the probable error of

TABLE II. p3Fp multiplets. The energy level values are below

the designations. The calculated wave number for each transitionis in parentheses. The observed intensities are in parentheses afterthe observed wave numbers. Observed and calculated intervalsare italicized.

P3F,0 p3F3o p3F4O47 187.54 94.36 47 281.90 181.16 47 463.06

a3F2 47 187.55 (2)0.00 (47 187.54)

a3F3 47 111.61(3)170.13 (47 111.77)

a3F4 47 076.03 (4)386.87 (47 076.19)

b3F2 35 655.74 (5)11 531.76 (35 655.78)

b3F3 35 547.78(1) 94.55 35 642.33(6) 181.04 35 823.37(2)11 639.80 (35 547.73) (35 642.10) (35 823.26)

b3F4 35 686.20(6)11 776.81 (35 686.26)

aIG4 35 163.43(-)12 118.39 (35 163.51)

the measurements themselves can be determined." Forthe 44 lines of the first group it is 0.076 cm-' and for the42 lines of the second group, 0.061 cm-'. When these areexpressed in angstroms, by using the mean wavenumber for all of the lines measured (40 000 cm-), theybecome 0.005 A and 0.004 A, respectively. Since thereis no reason to believe that the measurements for thesetwo groups of lines are any more or less accurate thanthose for the other lines, a probable error of no morethan 0.005 A can be assigned to the wavelength valuesin general. 6 The probable error in wave numbers will

1" H. Margenau and G. M. Murphy, The Mathematics of Physicsand Chemnistry (D. Van Nostrand Company, Inc., Princeton, NewJersey, 1956), 2nd ed., p. 515.

16 It is possible to compare the wavelengths of 66 lines withvalues calculated from the new interferometric term-values.5The calculated wavelengths are generally higher, and this indicatesthat there may be a systematic error in the present measurements.However, since the upper levels involved are the least reliableof the interferometric values and since only 16% of the lines canbe checked, no definite conclusion can be drawn until the resultsof further interferometric measurements become available.

292 Vol. 51


vary from 0.055 cm-' to 0.110 cm-', depending on theregion. Computed in the same manner, the probableerror for the measurements listed by Russell is 0.010 A.

Since the pairs of lines used in the calculations arefrom different portions of the spectrum and weremeasured on different plates, the internal consistencyof the measurements is also very good.

VII. TWO NEW LEVELS

It is not surprising that 211 of the 410 lines could notbe classified on the basis of previously known terms. Onehundred and ninety-seven of the 199 classified lines weretransitions to the five lowest even terms. Transitionsto these terms are to be expected mainly from the oddupper levels which are due to configurations involvinga 4p or a 5p electron added to one of the 15 parentTi ii terms. 7 However, only one of the 80 predicted 5pterms has been identified, and several of the 4p termshave not been found.' Many of these could be expectedto give transitions in the region covered by these plates.The intensity of the transitions from the 5p terms

TABLE III. Revised energy level values. The values assignedby Russell (footnote 13) are also listed.

Revised Russell Revised RussellDesig- value value Desig- value valuenated (cm-') (cm-') nated (cm-') (cm-')

v'D20 41 906.51 41 906.61 o3D30 44 233.65 44 233.15v5D30 41 985.83 41 985.93 q3F,2 44 824.13 44 825.26v'D40 42 092.42 42 092.52 q1F30 44 922.73 44 923.00p3D10 42 194.04 42 193.94 q3FP' 45 040.81 45041.02p3D20 42 269.78 42 269.72 w3S,0 44 858.03 44 857.89p3D30 42 376.45 42 376.71 n'D,0 44 966.39 44 966.36o'Dl 43 975.71 43 975.62 n3D20 45 063.80 45 063.94o'D20 44 079.84 44 079.39 n3D30 45 206.27 45 206.34

would be less than those from the terms which arealready known, and this fits in with the fact that themajority of the unclassified lines are of low intensity.Similar reasoning shows that, in general, only theprincipal components of multiplets due to the 5p termswill be observable. This makes their discovery quitedifficult.

To the present, the analysis of the new lines has ledto the discovery of two new terms, which explain 15of the unclassified lines. The new terms have tentativelybeen designated sG' and pF 0, according to theirlocation in the general scheme of Ti i terms. No attempthas yet been made to assign them to definite configura-tions. The multiplets which establish these terms havebeen set down in schematic form in Tables I and II.

From Table I it is seen that two partial multipletsinvolving sG0 have been discovered. The energy levelvalues calculated from their components (weighted)are such that the Land6 rule is almost exactly observed.

17 Work cited in footnote 14, p. xxxvii.18 Work cited in footnote 14, p. 278.

TABLE IV. Comparison of observed values used in calculatingselected levels from Table III.

Wilson and Thekaekara RussellObserved AXb Observed AXb

Level valuesa (C-0) Level values, (C-0)(cm-l) (cm-,) (A) (Cm-') (cm-l) (A)

42 376.45 376.44 -0.001 42 376.71 376.44 -0.001376.43 -0.002 376.59 -0.011376.40 -0.004 376.88 0.010376.60d 0.012 376.66 -0.005

44 079.84 079.79 -0.003 44 079.39 078.50 -0.046079.73 -0.006 078.81 -0.035079.84 0.000 079.98 0.03308 0.13d 0.023 080.27 0.070

44 233.65 233.66 0.001 44 233.15 232.97 -0.009233.68 0.001 233.10 -0.003233.65 0.000 232.52 -0.032233.59 -0.004 233.93 0.061

233.23 -0.00844 824.13 824.21 0.004 44 825.26 825.36 0.005

824.05 -0.004 824.36 -0.045825.080 0.086 825.18 -0.007

a The new interferometric values' were used for the lower levels.b The difference between the observed and calculated wavelengths of the

line involved.0 Calculated from the wave numbers of the lines and lower levels as

Russell lists them.13d This value was assigned a weight of one-half in the calculations.e This value was disregarded in the calculations.

The wave numbers of the lines, as recalculated from thelevels, agree very closely with the observed values.Finally, the intensity patterns-particularly for thea1F multiplet-are almost exactly what would bepredicted. (The bF3-a3G30 transition might be con-sidered doubtful.)

Table II shows that the reality of the p'F' term isconfirmed by lines found in three different regions. Theagreement is good between calculated and observedvalues and also between predicted and observedintensity patterns. The level intervals do not follow theLand6 rule, but the discrepancy is not large and is notunexpected because of possible perturbations due tothe crowding of terms as the limit is approached.

VIII. REVISED ENERGY LEVEL VALUES

The levels of seven of the terms established byRussell and listed by Moore were determined entirelyfrom lines in the region covered by these plates. Sincethe new measurements are, in general, more accurateand more consistent than those listed by Russell, thewave number values of the seven terms have beenrevised. The revisions also make use of Edlen's dis-persion formula and of the interferometric values forthe lower levels which were not available in 1927. Therevised values are found in Table III. Since the levelsv5Do0 and v'D10 were determined by Russell from linesnot observed on these plates, they have not beenincluded in Table III.

For four of the levels (D3 0, o3D 20 , o3D30, and q'F2

0 )the differences between the revised values and thoseof Russell seem very large. In Table IV, the observedvalues from which these levels were calculated in each

293March 1961

C. M. WILSON AND M. P. THEIXAEI<ARA

TABLE V. Ti lines from 2117 A to 3072 A.

AX Visually(c-0) estimated(A) intensity,

-0.01

0.005

0.004

0.003

-0.029-0.01

0.002

-0.004

-0.026-0.01-0.03

-0.02-0.017-0.005

-0.0040.0080.0060.00

0.0130.0230.020.01

-0.005-0.006-0.004

0.0120.000.0170.006

-0.020.021

-0.05-0.02

0.013-0.02-0.01

0.0020.015

0.0180.018

161

0.029 104

0.014 92

0.019

Classifi- Multi-cation pletb

z5G3- kF 215 a3F2 - y'F,3

z G2 -5D,2

a3P2 - vlF3O3 a'D2 -wF3

23 (Cr?)0 (Cr?)0

*-- a'D2 - v3P2b3F4 -3F4°

3 b3F3 - q3F31a3F4 -w3F30

5b3F2 - q3F2 0

210 a3F4 -w3F40

a3P2- 3P2a3P2 - 3Pl

3bPF2 -q3F30

... b3F3 -q1F4o1 aID2 -3D20

03 b'F3 - it'D,3 b3F4 - 13D3'3 b3F2 - 3D,0

a3P, - '3P20

0016 a3F310 a3F3

a3F3a3P2

5 a'D26 a'P26 a3P,7 a3F2

a3P26 a3F29 a3F4

a3P,

7 a3P2a3Poa3P,

4 a3POa3P2a3P,

49 a3F310 a3F44.0 a3F34 a'D2

(Ti ii?)a3rF2 - V3F,20

a3r, -v3F4 0

a3F2 -V3F20

368

372

373

374375375376

375

376377377

375375378

379379379377

376376376380378380380376381376382381380380380381381381

382382

382383

382

382

382

Observedwavelength

(A)

2931.034d2928.3132922.9102915.945d1914.412d2912.4732912.0822905.655d2903.705d2903.1682899.309 d2897.781d2895.776 d288 9.245d288 6.036 d2883.209(2881.94)28 75.645d2869.959 d286 5.216 d28 6 4.054 d2861.8 40d2860.6 59 d2860.25828 57.597d2856.077d(2855.13)2853.4322849.338 d2847.768 d2847.535d2846.276 d28 45.938 d2843.028 d2842.643d

2840.228 d

2838.521d2836.597

(2836.40)2836.0872835.627(2834.75)2834.002d

(2832.26)2831.3992830.040

2828.061

2827.109d2826.36728 26.150d2825.373d2825.0652823.4652822.300d2821.5262821. 2 55d2819.8 6 3d2819.026d2817.8352819.3992813.8 65d

Observedwave no.

(cm-,)

34 107.6734 139.3734 202.4734 284.1634 302.1934 325.0334 329.6434 405.0334 428.6734 435.0434 480.8734 499.0534 522.9434 600.9734 639.4434 673.4134 688.7034 764.6134 833.4834 891.1434 905.2934 932.3034 946.7234 951.6234 984.1635 002.7835 014.4235 035.2235 085.5635 104.9035 107.7835 123.3035 127.4835 163.4335 168.19

35 198.09

35 219.2635 243.1535 245.6135 249.4835 255.2035 266.1335 275.4135 297.1335 307.8435 324.80

35 349.52

35 361.4235 370.7035 373.4235 383.1435 387.0035 407.0535 421.6735 431.3935 434.7935 452.2835 462.8135 477.7935 483.2835 527.85

AX Visually(c-0) estimated

(A) intensity,

30.007 100.016 8

31

0.014 20.020 8

90

-0.008 20.001 3

0406

0.020 10.01

20

0.009 ...

30.032 00.009 5

25

0.000.006 2-0.005 0

-0.013 0

4-0.007 ...

.. .

-0.016

0.0010.00

-0.005-0.004

0.00

-0.01-0.001-0.011

-0.020

0.0050.012

-0.0140.004

-0.011

0.0590.0070.008


a'G4 - u'G4 ' 384aID2 - s3,30 385

a'P2 - w'P' 386a'D2 - v'F,3 387

a3P -1P,0b3F4 - u1G4°

386

a'D2 - 'P2' 388a'D2 - 3P]5 388

a'D2 - q3D,' 389

a'F2 -'P1°a'D2 -q3D2

a'D2a'F2b'F3

a3P2

389

390391

1

a'G4 - p3F30 0

2 3F4. . .

b3'F3. . .

2 a5F4a5F'3

2 a5F 55 a'F2

a5F,4

a'F]4 a5F25 a5F3

a5F,8

a5F'45

* . a3'F41 a3P262 a5F23 a3F,334 a'1]344

991

- 3G5O

- S3GP°

- v5D30- v5D2°- v5DV°- 5DI0- v5Doo

- v5D20- v5D30- v5D20

- v5D40

- 5D40- o3D10

-v5D30-56D2

- v5DV°

a3P2 -03D2a3P - 3Ds'a3F2 -w5D10

1

1

392392392392392

392392392392

392

393394

392393

392

394394393

Scale is froin 0 to 10 wvit a asol in(licating very wveak lines. Intensitiesare not given for the lines referred to in footnote c.

b The numbers used to distinguish lines belonging to the same multipletwere assigned by Russell.13 Newly found multiplets are designated by lowercase letters.

ee Senty-six lines classified by Ruissell' bt not observe(l in this work(see See. V) have been included in the list. The wavelengths of these lineshave been placed in parentheses.

d Lines not reported by Russell. A few may be found in the MIT Tables.10

Vol. 51

Observedwavelength

(A)

(3071.92)03069.699 d3042.535

3031.023d

3025.0563024.572d3021.5583015.5243010.373d3010.147(3005.37)3003.641

3002.730

3001.8 72d3000.892(2999.78)(2998.41)2995.699d

(2993.94)2993.0472991.7802991.399d2990.9812990.4882990.036

(2989.91)298 7.973d2986.905d2985.988d2985.4642983.290(2981.45)(2980.28)2976.3182974.9262970.5542970.372(2969.37)2968.2262967.218(2966.38)2965.686(2968.68)(2965.24)2961.442

(2959.98)(2959.71)2958.770d2956.7952956.1182954.561d2948.2382947.7002946.520d2945.28 4 d2942.971d2941.9632938.514d2937.2932935.962d(2933.53)2932.522d

Observedwave no.

(cm-,)

32 543.5032 567.0232 857.77

32 982.56

33 047.6233 052.9033 085.8733 152.0733 208.8033 211.2933 264.1033 283.22

33 293.32

33 302.8433 313.7133 326.0833 341.3033 371.4633 391.0933 401.0333 415.1733 419.4333 424.1033 429.6133 434.6633 436.1033 457.7433 469.7133 479.9933 485.8633 510.2633 530.9833 544.1433 588.7633 604.4733 653.9333 655.9933 667.3733 680.3233 691.7633 701.3133 709.1733 709.2633 714.2733 757.4733 774.1733 777.2433 787.9633 810.5333 818.2733 836.0933 908.6533 914.8433 928.4233 942.6633 969.3433 980.9734 020.8634 035.0034 050.4334 078.6834 090.37

294

- P3D20- x1D21- S3G30

- v1D20

- w3F20- 7b3F30

- W3F40

- q3D10

- r3D?

- q3D20

- q3D10

- W3F20

- P3D20- W3F30

- v3F30- p3D10

- q3D30

- q3D10

- q3D20

- p3D10

- P 3D30

- p3D20

- V3F20

- z,3F40

- V3F30

- itIG30

I

I


TABLE V.-Continued.


394ii

393394

II

394

Ih

n

i

It

I

n

a1G4 - u'F30 396a3P2 - w3S,' 397

397397398399399400399401400400

400399

400400

f

f

a3F3 - w 3P20 ea3F4 - v3G30 402

Observedwavelength

(A)

26 8 9.330d2688.82626 8 8 .16 0d268 7.133d2685.13726 84.795d2 68 3.277d26 8 1.6 51d2679.92326 78 .8 00d2678.341d2677.279d2676.07226 75.945d2674.089d2 6 72.8 24d26 71.8 1 Id2669.5922669.261266 8.711d2668.3192 6 6 7.300d2 6 6 6.006 d2664.865d266 4.338 d26 6 3.56 9 d2663.421d2 6 6 2.9 22d2661.9622660.6352659.8 91d2 6 58.590d2657.6 09d2657.1782656.9032656.3592654.9212654.448d2654.145d2653.582d2653.425d2653.280d2652.9752652.745d2651.130d2649.740d2649.5802649.291d2648.6442647.531d2646.6312645.3 83d2644.2532643.8 52d2642.455d2642.264d2642.04022641.0892638 .573d2636.1672635.453d2632.4142631.52626 28 .570d2627.437d2619.9402619.800d2611.4762611.2882605.1212604.8832599.885

Observedwave no.

(cm-,)

37 172.9537 179.9137 189.1337 203.3437 230.9937 235.7337 256.8037 279.3937 303.4237 319.0637 325.4637 340.2637 357.1037 358.8837 384.8037 402.5037 416.6837 447.7737 452.4237 460.1437 465.6437 479.9437 498.1437 514.2037 521.6237 532.4538 534.5337 541.5637 555.1137 573.8337 584.3437 602.7437 616.6137 622.7237 626.6137 634.3137 654.7037 661.4137 665.7137 673.7037 675.9337 677.9937 682.3237 685.5837 708.5437 728.3237 730.6037 734.7137 743.9337 759.8037 772.6437 790.4537 806.6037 812.3437 832.3337 835.0637 838.2737 851.8937 887.9837 922.5637 932.8437 976.6237 989.4438 032.1638 048.5638 157.4338 159.4738 281.0938 283.8538 374.4738 377.9738 451.75

AX Visually(c-0) estimated

(A) intensitya

0.000 29

-0.010 11

-0.001 8-0.003 8

-0.002 9-0.029 1

0.003 14

-0.004 31

-0.006 822

0.002 80.002 6

0.006 5

3

10.011 2

21

0.006 100.002 6

20.016 0

10.010 8

65

-0.005 7330

0.001 534556

0.000 63

-0.014 103

-0.003 101

-0.020 32

-0.008 102

-0.009 31

-0.011 8-0.010 8

23

-0.005 7-0.027 6-0.005 6

0.000 50.015 70.002 50.030 7

Classifi-cation

a3F2 -W3P10

a3F, -yS,20a&F4 -v3G4oa3F4 -x1F3'

a3F4 -v3G50a5F5 - t3G4 'a'F2 -W3P2°

a3F4 - 3F3'

a3F3 -V3G3°

a3F3 -V3G40a3F3 -x1FP

a'F4 -u3FV

a'F5 - t3G50 c

a3F2a3F3

aID2

a3F2

- 3G,°- u3F30

--W3S10

- xF3

Multi-pletb

e

402404

402C

403

402

402404

403

402403

404

a3F2 - u3F21 403

a3F3 - u3F4 0 403

a'F2

a3F4

a3F3

aID2

a3F2

a1D2

a3F2a3F3

a3F4a3F2a3F3a3F4aOF3a3F4a3F2

- ut'F3,- 3D3

- "3D20

- t3P 1

- 3DI

- t3P2

- j3D20

- t3F30- u3D3- 3F30- tF40- t3F3°- PD3°- t3F20

403

405

405

406

405

406

405405

407405407407407408407

(c-0)(A)

Visuallyestimatedintensity'

a3P0 -oDla'F3 - q3D20a'F2 -q3DI

b3F3 - p3F2a5F4 - q3D30

a&F2 -w5D2°a3p, -03D2°a5F2 - p3D0

a5F3 -p3D2

a3P2 - 0 3D30a5F4 -p3D3a5F, -p3DIOb3F3 -PF3'a'Fj -q3D2°a5F3 -q3D3b3F2 -p2°

a'D2 - w1P1ob3F4 - p3F4a'F, -p3D20a5F3 -P3D3

a5F2 -p3D30

b3F3 -p3F4°a3F3 -yIG40

Observedwavelength

(A)

2812.9702812.446d

2812.2 87d

2810.651d2809.998d2809.1542808.525d2807.471d2805.825d2805.6942805.494d2805.236 d28 04.8 26 d2804.204d

2803.7712803.249d2802.4982801.378d2799.266d2799.088 d279 6.274d2794.215d2793.6 75d279 0.6 51d2790.128 d2785.830d2782.361d2763.372d2758 .612d2758.066d2757.3742755.147d2752.680d2749.0312744.8382742.2972741.8162740.8692739.8082736.683(2735.61)2735.2832733.2642732.324d2731.5832731.1412729.360d2727.4202725.0812 723.909d2722.49 2d2721.98 7d2716 .624d2716.107d2 714 .6 73d2712.317d2710.335d2709.045d2703.493d2 702.633d2702.513d2702.010d2698 .8 4 5d2698 .1lod26 94.76 5d26 93.370d2691.76 5d2690.612d268 9.675d

Observedwave no.

(cm-,)

35 539.1535 545.77

35 547.78

35 568.4735 576.7335.587.4235 595.3935 608.7635 629.6435 631.3135 633.8535 637.1235 642.3335 650.24

35 655.7435 662.3835 671.9435 686.2035 713.1235 715.4035 751.3435 777.6835 784.5935 823.3735 830.0835 885.3635 930.1036 176.9936 239.4136 246.5836 255.6836 284.9836 317.5036 365.7036 421.2536 455.0036 461.3936 473.9936 488.1136 529.7836 544.1236 548.4736 575.4736.588.0536 597.9836 603.9036 627.7836 653.8336 685.2936 701.0836 720.1836 726.9936 799.4936 806.4936 825.9436 857.9236 884.8736 902.7436 978.2236 989.9836 991.6336 998.5137 041.9037 051.9937 097.9837 117.1937 139.3237 155.2437 168.18

0.012 9-0.008 1

0.010 1

-0.002 3-0.032 1

0.036 90.017 40.003 5

00.040 90.007 20.001 10.018 60.006 1

-0.003 56

0.018 10-0.002 6

0.018 ...0.025 4

30.022 ...

0.011 20.006 ...

222

0.008 100.010 9

30.017 80.001 70.006 10

-0.016 10.004 4

-0.020 100.003 60.000.015 80.019 10

-0.016 4-0.025 6-0.008 5

-0.021 8-0.026 9

-0.005 122

-0.003 ...

0

20.032 2

12011

00

-0.002 5-0.003 6

a'P, -W3S1°a3P -W3S1°

akD2- vD2aP2 -n3D2a3P, -n3D,0a3P2 - PP10a3Po - n3Dl,aID2- lD20a3P, -3Po0a3P2- -tP2°63F4 - ulF30a3P, -t3p10a'P2 -n3D3'

a3Po - t3P,°a3p, - t3P2'

a1D2 - 3D10

a'F3 -r3F2°

(Fe ii?)a1D2 -oD3°

March 1961 295

C. M. WILSON AND M. P. THEI(AEKARA

TABLE V.-Contiuted.

Visuallyestimated Classifi-intensitya cation

a3F3 - t 3F40a3F3 - t 3D20a3F2 - t3 F3

a3F3 - PD3 'a3F2 -3D,0a3 F2 - t3D2

a32' - 3D3

Multi-pletb

407408407

408408408

408

a']?, - X'P10a3F3 -lD20

a3F4 - s3D30 409

a3F3

a3rF3

a3rF2a3rF2a3rF2

a3F4 -3D,°a3F4 -wIG40a3F3 - 3D20

409

409

409409409

410411410

a3F2 - 3D, 410

a3F4 - y'IIoa']?2 -r3D20a3F3 - -3D30a3F2 - -3D30a3F4 - u3G4°

a3F4 - l3G,5a3F,3 - u3G30a3F4 - s3F3°a3F3 - u3G4°

a'D2 - u'F30a3F3 -s3F20a3F2 - iOG30a3F4 - vF30

a3F4 -S3F40a3F'3 - 3Fv30a3F2 -S3F2°

410410410412

412412413412

414413412b

413413413

Observedwavelength

(A)

2413.8 59d2412.545d2411. 8 64d2411.5682411.3582409. 8 97d2409.533d2409.272d2408.8 37d2406.082d2 405.544d24 05.340d2 405.066 d2 4 04.379d2403.9 8 7d2 400.540d2399.547d2399.371d2 397.029d2394.6 65d2390.716 d2384.5162380.8182378.1452374.5912372.2542371.9572369.283

(2368.57)

2365.03823 28 .798 d2314.2892308.8972305.6652302.7302299.8522294.2002293.745228 7.08 8 d2279.9642 278 .749 d2276.7032273.2802 272.9 09 d2 272.774 d2272.613(2272.45)2 272.3 74 d2268.7492267.91222 6 7.548 d2 26 7.356d2 264.020d

(2260.08)2259.6 43d2 259.4 96 d2259.317d2244.6902238.750

2238.214'12233.8092230.4922230.2442229.746d

(2227.91)2227.335d2226.7982225.128 d2223.1992221.474 d

Observedwave no.

(cm-')

41 414.8541 437.4141 449.1141 454.1941 457.8041 481.3941 489.2041 493.7041 501.1941 548.7041 558.0041 561.5241 566.2541 578.1341 584.9141 644.6241 661.8541 664.9141 706.6141 746.7841 815.7341 924.4541 989.5642 036.7542 099.6642 141.1442 146.4142 193.9742 206.74

42 269.7042 927.4343 196.5443 297.4143 358.0943 413.3543 467.5443 574.7543 583.3943 710.2443 846.8043 870.1843 909.6043 975.7143 982.8943 985.5043 988.6243 991.8243 993.2444 063.5344 079.7944 086.8744 090.6044 155.5644 232.5244 241.0844 243.9644 247.4744 535.7744 653.92

44 664.6144 752.6844 819.2344 824.2144 834.2244 871.2244 882.7544 893.5744 927.2644 966.2445 001.15

AX(c-0)

(A)

Visuallyestimated Classifi-intensitya cation

-0.015 0

0.007 40.009 4

1

20

-0.019 *-0

.001 . .

-0.002

-0.0040.003

-0.0150.0010.0040.0000.0020.0020.00

-0.002-0.006

0.0150.0000.0220.018

-0.0010.0170.013

-0.0020.028

0.0180.005

-0.004-0.03

0.0260.021

-0.03

0.018-0.036

-0.0090.012

-0.052

0.01

-0.011

-0.006

0

07564263

0

3297844

6076

5

032415

12235

35S54

13555

-~~~~~~~~~aF - ' 4 1

a3F3 - 3F4° 413a3F2 - sF31 413

a3F2 - OF? b

a3F4

a3F3a3F4a3F4a3F3a3F3a3F3a3F2a3F2a3F3a3F2a3F2a3r,2

a3F4a3F,a3F4a3F3a3F2a3F3a3F2a3F2a3F4

a3F3a3F2

a3F4a3F3

a3F3a3F2

- v5D40

- V5D3°

- q3D30- p3D30- q3D20- p3D2°

-q3D30- q3D10- p3D10- p3D30- q3D20- p3D2°

- 1,3F30- r3F20- )3FV°- )3F30- r3F2°- 13F40- r3F3°- vID2°

- o3D30

- 03D20- 3D10

-t3G5°- tGp- 03D30- 03D20

Multi-pletb

a'F3 - vF° b

a

a415416415416415415416416415416

417417417417417417417

418

418418

419419

418418

a3F2 - 03D3° 418

a3F4a3F4a3F'3

a3rF3a3F4a3F2

a3F3

a3F 3

a3F2

- q3F30- q3F40- q3F20

- q3F30- 13D3'- q3F2°

- q3F40

- 13 D2°

- 113DIO

420420420

420421420

420

421

421

AX(c-0)

(A)

Observedwavelength

(A)

2596.5642594.6262593.6342592.189d2590.2472586.2742583.221258 0.8 03d2578.8812 578 .735d256 2.119d2558.233d2557.054d2556.440d2554.907d2553.265d2552.6 16d254 4.252d2541.910253 8 .728 d2533.986 d2529.8722 528 . 9 60d2527.9802 521.359d2520.5342519.0172517.1432 511.008d2504.5102 501.452d249 9.6 38 d249 8 .328 d249 7.524d2497.227d249 4.589d249 4.06 9d249 2.140d249 0.796d248 7.245d248 5.623d2470.9872468.5732468.359246 6.974d246 5.478d2464.9782463.055d246 1.8 8 3d2 46 0.429 d2459.8 14d2459.6 70d2459.08 9d2458.0322457.8242447.590d2446.1262441.634d2440.9762438.2852434.0672433.2112432.194d2431.7722428.3482428.2112426.560d2424.2472421.2962418.3622415.6 8 5d2414.749d

Observedwave no.

(cm-,)

38 500.9238 529.6838 544.4238 565.9038 594.8138 654.1038 699.7838 736.0438 764.9038 767.1039 018.5039 077.7639 095.7839 105.1739 128.6339 153.7939 163.7539 292.4939 328.6939 377.9839 451.6639 515.8139 530.0639 545.3939 649.2239 662.2039 686.0839 715.6339 812.6639 915.9439 964.7439 993.7440 014.7140 027.5940 032.3540 074.6840 083.0340 114.0640 135.7040 193.0040 219.2240 457.4340 496.9940 500.5040 523.2440 547.8240 556.0540 587.7140 607.0340 631.0340 641.1840 643.5640 653.1640 670.6540 674.0940 844.1440 868.5940 943.7740 954.8141000.0041071.0541.085.4941.102.6741 109.8041167.7641 170.0941 198.1041 237.4041287.6641 337.7441 383.5541 399.59

0.023 90.003 40.002 7

00.008 60.008 50.001 6

60.005 4

00.004 40.008 6

4

00

0.008 440

-0.009 60

0.005 64

0.004 8-0.001 7

0.012 4073230

34

11

0.007 50.034 10.006 6

04

-0.001 524

20.010 30.003 40.002 40.003 00.003 4

0.007 90.008 40.016 70.013 7

0.005 30.028 40.005 4

-0.016 00.004 70.008 70.018 6

-

296 Vol. 51

-

- s3D211

- s3D30

- S3DO- S3D20- S3D30


TABLE V.-Continued.

Observed Observed AX Visuallywavelength wave no. (c-0) estimated Classifi- Multi-

(A) (Cm-') (A) intensity, cation pletb

2219.745 45 036.20 0.000 3 a3F, -n3D3° 4212219.156d 45 048.15 ...2218.916d 45 053.02 02218.382 45 063.87 -0.004 3 a'F2 - n'D2° 4212215.771d 45 116.96 1

(2211.36) 45 206.94 0.03 a'F2 - n3D30 4212162.453d 46 229.26 32156.649d 46 353.66 42155.8 34d 46 371.18 02155.08 2d 46 387.36 62152.119d 46451.22 0.000 1 a3F4 -s3G 4 0 k2150.198d 46 492.72 02149.136d 46 515.69 52147.304d 46 555.37 0.004 ... a3F3 - s3 G30 k2145.810d 46 587.78 0.000 6 a'F4 - s3G,5 k2145.054d 46 604.20 02143.614d 46 635.50 72142.373d 46 662.51 62142.123d 46 667.96 0.000 6 a3F3 - 3G4 0 k2139.489d 46 725.40 -0.001 6 a&F2 - 3G30 k2138 .352d 46 750.26 02130.041d 46 932.64 42126.943d 47 000.99 42126.108 47 019.44 52123.552 47 076.03 -0.006 4 a3F4 - 'F4 2 m2121.948 47 111.61 -0.006 3 a3F3 - F3 in2121.670d 47 117.79 22119.260d 47 171.36 12118 .533d 47 187.55 0.000 2 a3F2 - 3F2 Xl2117.021 47 221.24 3

used by Russell. (This is also true for the 12 levels notlisted in Table IV.) The consistency of the three valuesfor the level qF20 is equally poor in both papers. Sincethe last two values in each case are based upon lineswhich are blends, there is no basis, aside from thegreater consistency of the present measurements, forchoosing between them.

Table V is the complete list of the 410 Ti lines foundon Kiess's plates. In addition, it includes the 26 classifiedlines from Russell's list referred to in Sec. V. It isdoubtful whether four of the lines are due to Ti i.

An attempt was made to construct a uniform intensityscale over the whole region. However, the intensitieswere estimated by an inexperienced observer and arethe least reliable portion of the measurements. Exceptin the case of transitions involving levels of the twonew terms, AX was obtained by comparing the observedwavelengths with a list of predicted wavelengthscalculated from Moore's list of levels,14 as supplementedby the interferometric values of Kiess and Thekaekara.5The AX values for lines which are transitions from the16 levels discussed in Sec. VIII are, therefore, largerthan they would be if the revised values had beenused.

ACKNOWLEDGMENTS

The authors are indebted to Dr. C. C. Kiess for thespectrograms on which the paper is based and for hisaid and criticism at all stages of the work. Thanks arealso due to Rev. F. J. Heyden, S. J., director of theGeorgetown College Observatory, for the use of itsfacilities.

paper are listed. This table shows, at least for thefirst three levels, that the observed values upon whichthe revisions are based are more consistent than those

297March 1961

Documents

Ultraviolet Spectrum of TiI